How the chest should fit
The perfect fit of a dress shirt at the chest is a matter of personal preference. If you prefer a more relaxed fit, you can make the chest as large as you like. If you desire a tailored, slim look, you’ll want to reduce the Chest Width as much as possible without going so tight that it impacts comfort or produces unattractive pull lines across the chest. The fit of the chest should be about equal all the way around the shirt, at the front of the chest and at the back.
How the chest posture adjustment works
Changing this setting moves fabric from the back of the shirt to the front, or from the front of the shirt to the back. The overall chest measurement remains the same; fabric is simply redistributed to achieve the optimal fit. This adjustment increases the chest front or chest back by 1” increments.
Determining the optimal chest posture setting
With the collar of the shirt buttoned all the way up, stand up straight with your arms at your side. Look straight ahead and be sure to keep your shoulders relaxed and comfortable (don’t push your shoulders back or hunch them forward at all).
In this position, if you experience tightness at the chest front and simultaneously have excess fabric around the chest back/upper back area, a Chest Forward adjustment can improve your fit. This adjustment redistributes fabric towards the front of the shirt without increasing the total chest measurement. This alleviates chest front tightness and allows for a cleaner look on the back of the shirt. If you have a very slim fit, be aware that this adjustment will give you less range of motion when reaching up above or in front of you.
If you experience tightness at the chest back/upper back and simultaneously have excess fabric around the chest front area, a Chest Back adjustment can improve your fit. This adjustment redistributes more fabric towards the back of the shirt without increasing the total chest measurement. This alleviates chest back tightness and allows for a cleaner look on the front of the shirt.